Multiple-plunger fuel injection pump unit



Mmh 18, -1952 R. E. PETERSON 2,589,858

MULTIPLE-PLUNGER FUEL INJECTION PUMP UNIT Filed Nov. 7', 1946 Patented Mar. 18, 1952 UNITED STATES PATENT OFFICE Raymond E. Peterson, Riverside, Ill., assignorl to International Harvester Company, a` corporation of New Jersey Application November 7, 1946, Serial No. 708,259

Claims.

This invention has to do with liquid fuel injection systems of internal combustion engines, and more particularly c-oncerns a pump unit employing a plurality of injection plungers operable in conjunction with valve controlled manifold means for directing fuel pumped by the plungers to proper combustion chambers.

The present invention is related to and is an improvement upon fuel injection pump units of the character shown in E. A. Johnston et al. Patent 2,278,478, for Fuel Pump for Engines, wherein a single reciprocating pump plunger is employed for pumping fuel to a plurality of combustion chambers. In units employing a single pump or plunger, the number of combustion chambers capable of being served properly by the unit is, of course, limited since the pump plunger must reciprocate at a speed exceeding that of a reciprocating engine upon which it is installed by a factor corresponding to the number of combustion chambers of the engine. It has been found in practice that when a single plunger pump unit is installed upon engines having more than four cylinders or combustion chambers the speed of reciprocation of the pump plunger` becomes too rapid for properly metering and injecting the fuel. The general object of the present invention is the provision of an iniection pump unit wherein there are a plurality of pump plungers, less in number than the number of combustion chambers to be served, together with distributing means for directing the fuel pumped by the plungers to the engine combustion chambers at the proper times in the operating cycles of the engine.

A more specific object is the provision of a fuel injection unit employing a plurality of pump plungers in a novel arrangement having valve controlled laterals leading to respective combustion chambers of an engine.

A further object is the provision of a fuel injection unit wherein there are a plurality of pump plungers operated from a common pump driving shaft, and manifold means receiving periodic pressure impulses of fuel from the pump plungers for distribution to the combustion chambers through valve controlled laterals, and a valve operating cam shaft constrained for rotation in unison with the pump driving shaft whereby cams on said cam shaft respectively for said valves and properly phased on the cam shaft are operable to momentarily open the manifold-lateral valves in proper sequences and inV proper time relation with the fuel injection (ox. s-2) 2 impulses directed into the manifold by the plungers.

The above objects will be more readily comprehended after reading the following description, as Well as other desirable objects, advantages and capabilities of apparatus constructed according to the principles of the invention.

Referring now to the drawings:

Figure 1 is a vertical sectional view taken axially through a frame or casing of a pump and distributor unit constituting a. preferred form of the invention, the pumps of the unit being shown in side elevationvand the distributor block also being, shown in side elevation and partly in section;

Figure 2 is a sectional View taken on the li'ne 2-2 of Figure 1 for illustrating a header chan'- nel of the manifold together with a lateral leading from said channel, a valvefor the lateral and the. phase relation of cam lobes for sequentially momentarily opening the various lateral valves.

The apparatus is enclosed by a. frame or casing having a lowerl portion I2 and an upper porition I3. A pair of identical pumps PI and P2 are mounted in one end of the casing. These pumps receive fuel through a conduit I4vfrom a reservoir or tank (not shown). The details of the pumps PI and P2 are disclosed in vRay- .,mond Peterson Patent 2,381,555, for "Fuel Injection Pump, wherefore it will suffice for the present disclosure to explain that each of these pumps has an outlet passage I5 which communicates with the upper end of a; cylindrical bore I6, Each bore I6 contains a long plunger I'I which moves downwardly to the position illustrated with -respect to the pump PI for filling a fuel receiving chamber I8 formed in the bore IB above the upper end I9 of the plunger. Upon subsequent upward movement of the plunger I1 the fuel is ejected through the passage I5 and a conduit 2l. The plunger II of the pump P2 is shown in its uppermost position, but this plunger like that of the pump PI is also operable to ll its associated chamber I8 pursuant to downward movement of the plunger and to eject the fluid from this chamber through the associated passage I5 and a conduit 22 when theV plunger is forced upwardly. The plungers are spring urged downwardly, whereforethe lower ends exert a downward force against the bottoms of tappet cups 23 for retaining the bottoms of these cups against rollers A and B which are journaled upon eccentric bea-rings 2li'and125 on a pumpv driving shaft 26; Springs 21 for urging the tappet cups 23 downwardly are contained within said cups and these cups are slidable vertically within respective bushings 23 secured Within openings 29 of a horizontal casing wall 3 I.

The pump driving shaft which is journaled in bearings 32, 33 and 34 is driven by gears 35 and 36 respectively constrained for rotation with the shaft 26 and a cam shaft 31. Shaft 31 is rotatably supported within the casing by means of ball bearing members 38 and 39. 'I'he apparatus is designed for use with a four cycle internal reciprocating engine, wherefore the cam shaft 31 is to be driven at one-half crank-shaft speed of the engine and the gears and 35 are designed for rotating the pump driving shaft 2B at three times the speed of the cam shaft or one and one-half times the speed of the engine crank-shaft.

A distributor block 4I mounted on a horizontal wall portion 42 of the casing or frame contains a header means comprising axially alined header channels 43 and 44 with which the conduits 22 and 2| are respectively connected. Each header channel has three laterals respectively designated 45 and disclosed within a row within a plane common to the axes of the cam shaft 31 and of the pump driving shaft 25. Each of these laterals 45 communicates with the bottom or upper end of an inverted recess 45 containing a poppet valve assembly 41 with a valve head 52 which is normally held closed by a spring 4B but openable by upward movement of a valve stem 49 to provide communication between the lateral 45 and an associated diagonally directed passage 5I which communicates with a side wall portion of the inverted recess 46 at a position below the poppet valve head. Each diagonal passage `5I communicates with a channel 53 in a coupling member 54 screwed into a recess 55 therefor in the upper side of the distributor block 4|. These coupling members 54 are for communicative connection with respective combustion chambers of the engine by means of conduits (not shown). The left-most coupling member 54 is for communicative connection with the number I cylinder or combustion chamber of the engine; the second coupling member 54 from the left is for communication with the number 2 combustion chamber and so on, the right-most coupling member 54 being for communication with the number 6 cylinder or combustion chamber of the engine.

Tappets 55 for operating the valve stems 49 are journaled for vertical reciprocation in bearings 56 of the casing wall 42 and the extreme lower ends of said tappets have cam follower heads 51 which slide upon the peripheries of cams designated I to B. Cam I has a lobe IA; cam 2 a lobe 5A; cam 3 a lobe 3A; cam 4 a lobe BB; cam 5 a lobe 2B; and cam 6 a lobe 4B. The digital counterparts of the reference characters designating the cam lobes have the further signicance of designating the position in sequential operation of these cam lobes. Assuming the cam shaft 31 to rotate clockwise, as viewed in Figure 2, the cam lobe IA will operate rst, the cam lobe 2B second, the cam lobe 3A third, etc.

Referring to Figure 1 it will be observed that the pump operating element A, which is 180 out of phase of the pump operating element B, is in the position causing the plunger of pump P2 to have discharged fuel from the pump chamber I8 through the conduit 22 into the header channel 43. During such discharge the cam lobe IA was under the valve stem head 51 assoelated therewith for opening the associated valve 41, Figure 2, for permitting the uid column propelled by the pump plunger to advance through the bore 53 of the coupling 54 for connection with the number I cylinder of the engine.

As can be seen in Figure 2, the cycle of operation has progressed to the point that the lobe IA has passed beyond its associated valve stem head 51 so that the associated valve 41 has closed, there being no more ejection of fuel from the pump P2 at this time. The plunger I1 of the pump P2 has begun its downward recession movement under the infiuence of the spring 21 associated therewith.

During continued operation of the apparatus, the pump operating element A will permit further downward movement of the associated pump plunger I1 for causing the pump chamber I8 to receive another charge of fuel. Meanwhile the pump operating element B is moving the plunger I1 associated therewith upwardly for compressing a charge of fuel in the chamber IB of the pump PI. Eventually fuel is ejected from the chamber I8 through the conduit 2| into the manifold channel 44 and concurrently with such ejection, the cam lobe 2B of cam 5 associated with the number 5 engine cylinder will ride under its associated valve stem head 51 and thereby open the valve 41 through which the uid can pass from the manifold channel 4,4 outwardly through the coupling 54 communicatively connected with the number 5V cylinder. Substantially concurrently with completion of the injection stroke of the pump PI, the cam lobe 2B will permit the associated valve 51 to close and the pump operating element B will permit the plunger of the pump PI to descend for recharging the charged receiving zone I8.

It will be observed therefore that the pumps PI and P2 alternate or operate successively in their injection of fuel into respective portions 43 and 44 of the manifold header means. The order in which the valves of the manifold laterals 45 are operated is in the order of counterclockwise distribution of the cam lobes IA, 2B, 3A and so on, counterclcckwise circumferentially about the cam shaft 31, as illustrated in Figure 2. The alphabetical component of the compound reference characters associated with the cam lobes on the cam shaft 31 designate which of the pump operating elements A or B is functioning to cause its associated pump to be ejecting while the designated cam lobe is opening its associated valve 41. The pump operating element A operates the pump P2 which always discharges into the manifold channel 43 whereas the pump operating element B operates the pump PI which always discharges into the manifold channel 44. Since the pumps discharge alternately or in succession, the cam lobes IA, 3A and 5A are distributed alternately circumferentially of the cam shaft 31 with respect to the cam lobes 2B, 4B and EB. The cam lobes IA, 3A and 5A operate Valves 41 of the three laterals associated with the manifold channel 43, whereas the cam lobes 2B, 4B and 6B operate the stems of valves 41 associated with the laterals of the manifold channel 44. An examination of the two gures of the drawings will reveal that the relative speeds of the shafts 31 and 25 (the gears 36 and 35 driving the shaft 2S at three times the speed of the cam shaft 31) and the circumferential phasing of the valve operating cams on the cam shaft is such that the valves are momentarily opened in rotation and that the opening of each valve is preceded and succeeded by the opening of a valve associated with a different header channel, and the opening'period of each valve is coincident-with a period of pump discharge into the header channel associated with such Valve. lA complete operating cycle involves the cam lobe IA opening its associated valve il for causing the discharge of the pump P2 to be directed to the number l engine cylinder; next, the cam lobe ZB opens its associated valve l for causing the discharge of the pump Pl to be directed to the number 5 cylinder; the number 3A cam lobe next opens its valve to direct the discharge 'of pump P2 into the number 3 cylinder; number 4B cam lobe next operates its valve 'for directing the discharge of pump Pi into the number 6 cylinder; cam lobe 5A next operates its valve for directing the discharge of pump P2 into the number 2 cylinder; and finally, cam lobe 6B opens its valve for directing the discharge impulse of pumpPl into the number d cylinder.

Having described a single preferred form of the invention with the view of clearly and concisely illustrating the same, I claim:

l. In a unit fuel injection pump, a distributor manifold having a plurality of headers and a plurality of discharge laterals leading from each header, a plurality of fuel pumps respectively associated with the headers and each having a discharge passage communicative with its associated header, each pump being operable for cyclically discharging fuel under pressure into its associated header exclusively of the laterals thereof, a plurality of valves respectively for the manifold laterals and openable to accommodate discharge through their associated laterals from their associated header, means for operating said pumps to cause successive discharge thereby into the headers, and means for sequentially opening said valves coordinately with the operation of said pumps so the opening period of each valve is accompanied by a respective discharge of the pump for the associated header.

2. In a unit fuel injection pump, a distributor manifold having a plurality of non-communicative header channels, each having a plurality of discharge laterals, each header channel having an equal number of said laterals, a pump driving shaft extending in parallelism with said header channels and having thereon a plurality of pump operating elements corresponding in number to the number of header channels, a plurality of fuel injection pumps respectively operable by said elements and said elements being phased circumferentially of the pump driving shaft for operating pumps to cause successive fuel injection strokes thereby, conduits respectively connecting discharge ports of said pumps with said header channels, a plurality of valves respectively for the manifold laterals and openable to accommodate discharge through their associated laterals from the header channel thereof, said laterals and said Valves being spaced lengthwise of the pump driving shaft, a valve operating cam shaft arranged in parallelism with the pump driving shaft and having a plurality of valveoperating cams spaced lengthwise thereof for the respective operation of said valves to momentarily open the same, driving means interconnecting said cam shaft and said pump driving shaft whereby these shafts are constrained for rotation in timed relation, the relative speeds of said shafts and the circumferential phasing of the valve operating cams on the cam shaft being such that said valves are momentarily opened sequentially and concurrently with pump discharge vinto the header channel of each opened valve.

3. In a unit fuel injection pump, a distributor manifold having a plurality of non-communicative fuel receiving header channels, each having a plurality of fuel discharge laterals, each header channel having an equal number of 'said laterals, a pump driving shaft extending in parallelism with said header channels and having thereon a plurality of pump operating elements'corr'esponding in number to the number of header channels, a plurality of fuel injection pumps respectively operable by said elements, each pump having a discharge port, conduits respectively connecting the discharge ports of said pumps with said header channels, a plurality of valves respectively for the manifold laterals and openable to accommodate discharge through their associated laterals from the header channel thereof, said laterals and said valves being spaced lengthwise of the pump driving shaft, a Valve operating cam shaft arranged in parallelism with the pump driving shaft and having a plurality of valve-operating cams spaced lengthwise thereof for the respective operation of said valves to momentarily open the same, driving means interconnecting said cam shaft and said pump driving shaft whereby these shafts are constrained for rotation in timed relation, the relative speeds of said shafts and the circumferential phasing of the pump operating elements on the pump driving shaft being such as to` cause successive discharge of the pumps into the manifold channels respectively communicative therewith through said conduits, the relative speeds of said shafts and the circumferential phasing of the valve operating cams on said cam shaft being such that the valves are momentarily opened in rotation and that the opening of each valve is preceded and succeeded by the opening of a valve associated with a different header channel, and the opening period of each valve being c0- incident with a period of pump discharge into the header channel associated with such valve.

Li. In a unit fuel injection pump, a distributor manifold having a pair of non-communicative axially alined fuel receiving header channels, each having a plurality of fuel discharge laterals, each header channel having an equal number of said laterals, a pump driving shaft extending in parallelism with said header channels and having thereon a pair of pump operating elements, a pair of fuel injection pumps respectively operable by said elements, each of said pumps having a discharge port, conduits establishing communication respectively between said pump ports and said header channels, a row of valves respectively for the manifold laterals and openable to accommodate discharge through their associated laterals from the header chamiel thereof, said laterals and said valves being spaced lengthwise of the pump driving shaft, a valve operating cam shaft arranged in parallelism with the pump driving shaft and having a plurality of valveoperating cams spaced lengthwise thereof for the respective operation of said valves to momentarily open the same, driving means interconnecting said cam shaft and said pump driving shaft whereby these shafts are constrained for rotation in timed relation, the elements on said pump driving shaft being phased for alternately operating said pumps to alternately discharge into said header channels, the cams on said cam shaft being phased for successively opening said valves in a sequence that causes alternate discharge from said header channels, and the re1- ative speeds of said shafts and the phasing of said cams with respect thereto being such that the opening period of each valve is coincident with pump injection into the header channel associated with such valve.

5. The combination set forth in claim 3 wherein said header channels are axially alined and said laterals and said valves therefor are arranged in a row extending lengthwise of said channels; wherein said pumps extend radially from the pump driving shaft in a plane common to said shafts, said valves and said header channels and are arranged in a row extending in parallelism With said row of valves; and wherein there is frame means provided with bearings for said shafts, and mounting means for main- 8 taining the aforesaid row alinement of said pumps and said valves.

RAYMOND E. PETERSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,080,216 Hoadley Dec. 2, 1913 1,724,156 Winton Aug. 13, 1929 1,961,769 Kollberg June 5, 1934 2,223,758 Dillstrom Dec. 3, 1940 2,287,478 Johnston et al. June 23, 1942 2,291,939 Amery Aug. 4, 1942 2,381,555 Peterson Aug. 7, 1945 

